Underwater weapon



June 6, 1967 A. T. BIEHL ETAL UNDERWATER WEAPON 5 Sheets-Sheet 1 Filed April 2, 1965 s w s W/ V Am/ I June 6, 196? I A, BgEHL ETJAL 3,323,457

UNDERWATER WEAPON Filed April 2, 1965 5 Sheets-Sheet 2 June 6, 1967 A. T. BIEHL. ETAL UNDERWATER WEAPON 5 Sheets-Sheet 5 Filed April 2, 1965 427%? Z filE/KL weezrm/Am/eflr IN VE N TORS 3,323,457 UNDERWATER WEAPON Arthur T. Biehl, Calle Los Calad'os, and Robert Mainhardt, Caile Arroyo, both of Diablo, Calif. 94528 Filed Apr. 2, 1965, Ser. No. 445,277 7 Claims. (Cl. 102-48) This application is a continuation-in-part of copending application Ser. No. 225,672, filed Sept. 24, 1962, entitled, Underwater Weapon, and now abandoned.

The present invention relates in general to the field of underwater weapons and more particularly to a hand held underwater weapon wherein small rockets embodying novel construction features are employed to obtain unusual underwater ordnance effects.

Heretofore, hand held underwater weapons for fishing as well as for military applications have consisted of arbalete, spring driven, compressed gas, and explosive driven guns, all of which have certain disadvantages. Not the least of these disadvantages are that these weapons have relatively short range and very low penetrating power. Moreover, they are complicated to fire and hard to reload. Some of the advantages which could be obtained by using the underwater weapon comprising a rocket projectile are apparent from experience with large rockets. Among these would be the elimination of recoil and muzzle blast, both of which are very undesirable underwater. Simplification of the design can be accomplished through the reduction of the need for precision manufacturing of launching apparatus, and reduction of the overall size and weight of the weapon. The cost is comparable, and in most cases less, than previously existing weapons.

In accordance with the present invention the launcher housing, launch tubes, and rockets may be made entirely of a strong plastic or non-magnetic material so as not to interfere with the operators compass, i.e., his navigation. A rocket propelled projectile also has a decided advantage over spring or arbalete projectiles in that it attains its maximum velocity at some distance from the launcher whereby the projectiles have the greatest energy in the target area. Although some compressed gas projectiles may exhibit this feature, they have a much lower energy potential Wherefore the target range and effectiveness is considerably less. Compressed gas weapons also require undesireably heavy bulky containers for transporting the gas. The use of a rocket projectile in underwater applications also affords utilization of the combustion chamber flame to ignite a tracer as a pyrotechnic delay train which may be used to set off high explosives in a warhead. Impact initiated warheads are also contemplated and described herein.

In accordance with the present invention some embodiments of the rocket projectile are reusable, as propellant charges may be replaced therein, allowing the use of the entire casing and nozzle many times. Furthermore, stabilization of these rockets is achieved by a drag or roll induced through the configuration of the rocket nozzle or projectile exterior design. Normal finned stabilizing techniques could be used. The former two techniques obviate the need for fins, which reduces the complexity and size of the launchers required for these rockets. Novel ignition techniques are also contemplated which provide control of the launching sequence, as well as reliable ignition of the rocket underwater, and are disclosed herein.

An object of this invention is to provide an underwater weapon which is lightweight, small, easily reloadable, inexpensive, and yet attains high energy with deep penetrating power at long range.

Another object of this invention is to provide an underwater weapon which has very little recoil or muule blast, and does not produce an unpleasant ar unbearable underwater sound effect.

3,323,457 Patented June 6, 15%67 A further object of this invention is to provide a miniature rocket of novel construction features which is suitable for underwater operation and has a variety of lethal warheads.

A still further object of this invention is to provide a means for maintaining miniature underwater rockets in dynamic stability.

Still another object of this invention is to provide an underwater weapon comprising reusable rocket projectiles.

Yet another object of this invention is to provide novel ignition techniques for underwater operation of small rockets.

Other objects and advantages of this invention will be set forth in the following description of the invention and illustrated in the accompanying drawings, in which similar reference characters relate to similar components and of which drawings:

FIGURE 1 is a side view in section of one embodiment of the present invention depicting the rocket, rocket launcher, and ignition means.

FIGURE 2 is a side view, in section, of a miniature rocket having a time delay actuated explosive warhead.

FIGURE 3 is a projection of the section taken at plane 33 of FIGURE 2.

FIGURE 4 is a side view, in section, of an underwater rocket propelled underwater spear.

FIGURE 5 is a projection of the section taken at plane 5-5 of FIGURE 4.

FIGURE 6 is a side view, in section, of an impact detonating underwater rocket having a warhead.

FIGURE 7 is a side view, in section, of a warhead.

FIGURE 8 is a side view, partially in section of a simple mechanism for firing the underwater rockets of the present invention.

FIGURE 9 is a side view, partially in section, of the launcher of FIGURE 8 arranged for underwater reloadmg.

FIGURE 10 is a side view, partially in section, of a reloadable underwater hand gun for firing the rockets of the present invention.

FIGURE 11 is a side view, partially in section, of an alternative means of providing roll stabilization for the rockets of the present invention.

FIGURE 12 is a projection of the section 12-12 of FIGURE 11.

FIGURE 13 is a side, in section, of another alternative means of providing roll stabilization for the rockets of the present invention.

FIGURE 14 is a projection of the section 14-14 of FIGURE 13.

Referring now to the drawings by reference characters and referring particularly to FIGURE 1, there shown is a rocket generally designated 21 having casing 32 in which propellant 33 is disposed. The casing may be made of metal such as steel or aluminum or high strength plastics such as nylon, phenolic based resin or polystyrene. The casing must be able to withstand the chamber pressures developed inside the rocket which are on the order of 500 to 3000 p.s.i. Most materials are suitable for this if the correct wall thicknesses are selected but the casing must also be capable of securing a nozzle, being waterproof, and in some instances being able to withstand high temperatures. The last requirement may be overcome by a suitable propellant inhibitor (see US. patent application Small Arms Weapon, Ser. No. 435,780, filed February 11, 1965, for suitable inhibitors and propellants). The rocket is also provided with a nozzle 34 in the aft end of the casing to develop thrust. It may be formed as an integral part of the casing as shown or it may be made separate and inserted as described herein be.- low. Suitable nozzle materials include most metals such as steels, aluminum, brass and copper and many plastics including nylon, polystyrene, phenolic based resins, epox-.

ies, and ceramic materials, the propellant has a cylindrical perform-ation 36 into which a pyrotechnic fuse 37. is

inserted. The space 38 allows the passage of exhaust gases perforation diameter during burning if the grain perforation is such that it can continually expose a greater surface of propellant as the burn progresses and is not a neutral or regressive perforation. A booster may be located in perforation diameter along with the pyrotechnic fuse and may be simply a loosely packed material such as thermite (Al Fe O The booster material which defiagrates, scattering hot molten slag, insures the ignition of the propellant throughout the length of the perforation in a rapid and uniform manner thus allow the immediate attainment of the desired chamber pressure.

The front portion of the rocket is provided with a warhead 39 which terminates in the nose 41 and is secured to the rocket casing by a tight press fit or a mechanical seal. The warhead may be any one of a number of suitable materials and standard configurations such as barbed or togglehead which are especially valuable infishing operations. Additional novel head configurations suitable for use with the extremely high performance obtainable from the present invention will be disclosed and claimed hereinafter.

I In FIGURE 1' the warhead hasa pointed nose and a suitable material would be brass, steel or even tungsten carbide due to their high density which provides the proper balance to the projectile. Increased ordnance effects might be achieved by making the warhead of theexploding variety. The warhead contacts the casing along the interface 42 and is secured therein by means of a removable locking pin 43. The pin is provided as a safety device preventing the rocket from attaining high performance by having it drag the launching tube, if it is accidently ignited, or providing an insulated handhold for the operation to restrain the rocket. An ignition means is located in the nozzle which consists of a pyrotechnic compound 44 having a wire 46 extending therethrough. The wire has a zig-zag end 47 and is coated with a pyrotechnic material and in operation is pulled through the compound in the nozzle. The friction at the zigzag end with its pyrotechnic coating as it passes through the pyrotechnic material in the nozzle causes the combined materials to flash from the nozzle into the space between the nozzle and the propellant grain, and subsequently into the perforation, thus igniting the fuse. The wire is provided with a pulling means which may consist of a ring 48 or disc or other suitable structure by which the operator can pull the wire.

The rocket is disposed inside a launcher or launch tube 49 which may be of a suitable material such as plastic, metal or impregnated paper. The launcher is sealed at both ends by frangible diaphrams 51, 52 which have a suitable means for allowing the wire to pass therethrough while maintaining water tight characteristics. The aft end 56 of the rocket casing may be provided with a screw thread thus allowing the warhead to be removably secured to the casing portion of the rocket which contains the combustion chamber. With this embodiment it is contemplated that new propellant grains may be inserted into the casing section and the projectile used many times, unless of course, the warhead is destroyed by a payload such as high explosive. If the latter is the case, a new warhead section may be attached to the old casing section if the latter is located after use. Similarly the entire engine section comprising the casing,

- pentaerythritol nozzle, and propellant may be made as one unit and attached to the warhead.

FIGURE 2 is a cross section of a rocket suitable for underwater use and having a high performance explosive .Warhead. ,A substantially tubular casing 57 having forward 58 and rearward 59 ends is made of, metal, generally steel. Bundy lap-welded steel tubing has worked very well. A pointed nose portion 61 is secured in the forward most end of the casing. It can be held adequately, by simply crimping the casing into an annular groove 62 around the nose or by other mechanical engagement means such as threads, etc. The nose should be of a heavy metal in order that the center of gravity of the ,rocket be at least 60% of the length of the rocket from the rearward end. The nose is pointed for hydrodynamic streamliningand to permit the rocket to penetrate the target. If desired, a small high explosive warhead 63 can be used such as Composition C, compacted pellets of tetranitrate (PETN), black powder, double base gun powder, or simply the waste from the double base propellants produced in manufacturing the propellant grains of the rockets. An outside inhibited center burning propellant grain 64 is disposed in the rearward end of the casing. A nozzle means 66, is located in the rearward end of the casing adjacent to propellant grain and is. arranged for imparting rotation to the rocket in its underwater trajectory. Various nozzle means for accomplishing this will be described hereinafter.

'A novel. rocket ignition means for underwater use is located in the rearward end of the rocket and uniformly ignites the propellant grain. A booster pellet 67 is POSI- .tioned inside the forward end of the propellant grain, the

composition of which is disclosed in the previously referenced patent application. Quickrnatch 68 or propellant activation which is simply black powder and cotton string is positioned forward'of the nozzle inside the casing adjacent the nozzle ports. Then the first fire water proof 7 primary igniter is provided by using a standard empty pistol cartridge 69 with a primer 71 located in the center thereof. This covers the rearward end of the casing with a water tight press fit in order to keep the water out. The combination of the cartridge cap and the booster, as second fire igniter, solves the problem of using rockets underwater since the nozzle orifices must be covered or plugged until the propellant is lighted and then immediately uncovered to permit the escape of the combustion gases. This arrangement of the cartiridge cap and second fire igniter solves other problems attendant to miniature rockets, such as the phenomena of ignition spike. When miniature rockets are ignited they sometimes experience this phenomena whereby they produces a burst of thrust due to partial ignition and then the motor loses thrust for a short period until complete ignition is subsequently achieved. Sometimes the ignition spike is suflicient to propel the rockets out of the launcher, but is not sufficient to sustain the rocket in a state of stability during the period of reduced thrust. One method of overcoming this problem involves restraining the rocket until it is properly ignited. The friction fit of the cartridge cap on the rear of the rocket performs the restraining function until the rocket motor thrusts the rocket out of the cartridge. Thus by using this arrangement the rocket motor can be ignited by the simple firing pin mechanism common to most firearms and yet is and remains watertight until the rocket motor is properly ignited, while also restraining the rocket until the motor is properly thrusting. This unique combination makes miniature rockets of the present invention practicable for underwater use for the first time.

When a high explosive warhead is used on the front end of the rocket, a detonator delay fusing means can be disposed between the warhead and the propellant grain and comprises a pyrotechnic filled tubular metal delay element 72. This element is standard delay fusing obtainable from American Cyanamid Co. (similar to that used in delay blasting caps). Alternatively, impact detonator means can be employed as will be hereinafter described in connection with FIGURE 6.

When using a delay fusing technique, a layer or section of delay mix 73 such as boron, barium chromate (BBaCrO is located behind or rearwardly adjacent the delay mix and forwardly adjacent the propellant grain and the booster pellet, i.e., the bulkhead is sandwiched between the active portions of the delay element and the propellant elements contained in the combustion chamber of the rocket. The bulkhead is formed for permitting the transmission of heat or flame from the booster or the burning propellant of the combustion chamber to the delay mix, while preventing it from passing rearwardly through the bulkhead and into the combustion chamber during the acceleration of the rocket and the burning of the propellant grain. This is accomplished by forming the bulkhead of a metal disc and punching or piercing the hole or port or perforation there through. The punching or piercing process is performed in such a manner as to leave a flap 78 or overlapping projection formed by the metal displaced by the punching or piercing operation covering the perforation 77. This structural arrangement thereby obstructs the straight line fiow path and creates a semieffective unidirectional valve which permits the burning propellant to ignite the delay fusing train but prevents it from being blown out the rearward end of the rocket. The rockets are designed so that when fully assembled they have a center of gravity (CG) at least 60% of the length of the rocket from the rear end and as far forward as possible to achieve lance stabilization. The rotational moment imparted to the rocket from the nozzle means prevents excessive dispersion of the rockets from the intended target. The finless rockets are utilized to achieve a smaller weapon design and to eliminate external projections which might be damaged in the rough handling that an underwater hand weapon must generally be able to withstand.

In operation, the firing sequence progresses through the steps of having a firing pin strike the primer cap located in the cartridge case attached or secured to the rear of the rocket. The primer ignites a flash sensitive mix which can be painted in the nozzle ports and transmits the heat to the quickmatch element. The flash mix is not a necessary element but insures ignition. The quickmatch in turn transmits heat by deflagration, radiation and/or other means to the booster igniter pellet in the forward end of the perforation to ignite the forward end of the propellant grain. The burning of the booster and the propellant grain ignites the delay mix, which is part of the delay train, and subsequently the delay element. After the delay element has burned the length of the tube it detonates the warhead explosive. The time delay element is selected to permit the rocket time to traverse the trajectory and to penetrate the target, and yet detonate shortly thereafter to prevent the target, if a fish, from swimming away or being killed.

FIGURE 3 of the drawings shows the nozzle of the embodiment of FIGURE 2 through plane 33.

The nozzle 66 imparts a moment of angular rotation to the rocket body about its longitudinal axis. In order to achieve this effect, the nozzle is provided with four skewed ports 78. Any number greater than two are suitable. The orifices are arranged in a quasi-helical fashion whereby the ports are canted with respect to the longitudinal axis of the rocket with the axis of flow having an effective thrust vector component perpendicular to a radius of chamber cross section. Holes are made with a tapering diameter from small at the inner end to large at the exit or aft end, thereby forming a diverging nozzle cone. A converging-diverging nozzle port could be formed by counter tapering the holes. The gases issuing from the ports exert a twisting force component on the nozzle thereby imparting the rotation to the rocket casing.

It can be seen from this view how the nozzles are canted. By using the roll stabilization provided by this nozzle the dynamic performance of the missile and the dispersion reduction characteristics are greatly improved. Roll stabilization obviates the necessity for using fins to achieve rocket accuracy. While not being absolutely es sential, roll stabilization is effective in reducing dispersion by continuously orienting the rocket about a mean trajectory path rather than permitting any dispersion causing inbalance to permit the rocket to continue on a diverging track from the intended trajectory. Rockets which are not roll stabilized but which have a high length to diameter ratio, and a separation of their center of gravity and center of pressure (center of pressure being aft of the center of gravity), are also stable. The underwater rockets of the present invention are designed to inherently include this latter described parameter and therefore exhibit stabilization without roll, but combining the two means of stabilization provides a further degree of accuracy. Thus by using the nozzle described, it may be seen that the gases egressing from the nozzle ports will have some of their linear momentum converted into an angular rotational moment causing the rocket to slowly roll about its longitudinal axis. Alternate methods of achieving roll stabiliza tion are shown herein below and described in greater detail. Other types of roll stabilization nozzles and configurations can be seen from US. patent application entitled Miniature Ballistic Rocket, Ser. No, 445,276, filed Apr. 2, 1965.

FIGURE 4 shows a form of the invention wherein a standard pointed spear 79 is driven by rocket propulsion consistent with the teachings of the present invention. This rocket has an outer casing 81 which is a single piece made of Bundy lap-welded seamless tubing. This tubing has a very high bursting strength and yet is a very economical type of tubing cost wire. In practice, any high strength tubing can be used. The case is formed by selecting a piece of tubing the length of the rocket and then metal forming the nose end 82 into a closed section. The interior pontion 83 of the forward end of the casing is then filled with weight such as compacted shot, extruded rod, or simply molten lead, or some other low temperature melting metal having a high density, which will provide a weighted nose to the rocket. If compacted shot is used for weighting, then a fire wall should be secured rearward of the shot to prevent the gases of combustion from the rocket motor penetrating forward into the casing, thereby absorbing energy. If lead or some other heavy metal is poured into the forward end of the rocket a sealed fire wall is formed naturally at the rear surface thereof, and an individually positioned fire wall can be dispense-cl with. This weighted nose provides the proper balance to the rocket and lends interior rigidity to the casing to provide a strong spear. A rocket motor is used similar to that of the embodiment of FIGURE 2, but an alternative ignition means may be used. A fuse 84 or igniter extends the length of the propellant grain 86 to the booster 87 at the forward end of the grain. The igniter can be a piece of porous paper coated by spraying or dipping with a mixture of 2A and nitrocellulose. 2A is a common rocket igniter consisting of 20% amorphous boron and potassium nitrate, 50 parts by weight of 2A is used with 1 part of Dupont cotton base nitrocellulose. Acetone serves as a solvent during dipping or spraying. Substitution of black rifle powder for the 2A is satisfactory. The booster pellet can be dispensed with if this igniter is used instead of quickmatch in the nozzle. The nozzle is formed directly in the casing by simply rolling or crimping a reduced diameter section into the exterior wall of the rocket casing, and the angular rotational means is formed in the portion of the nozzle cone rearward of the annular groove by a simple stamping operation. Slits are cut longitudinally into the casing wall and the vanes bent down into the exit portion of the nozzle to deflect the gases exhausting therethrough, thereby imparting the angular rotation to the rocket. This is a relatively inexpensive way to form a rocket. An igniter cap is sealed to the rear end of the rockets surface by a friction fit as in the embodiment of FIGURE 2. When the primer is fired the igniter uniformly lights the propellant grain longitudinally along the perforation.

FIGURE is a projection of the nozzle of FIGURE 4 through plane 55. It can be seen how the vanes 88 are positioned in the path of the gas fiow emerging from the nozzle and exhausting through the nozzle cone.

FIGURE 6 is an embodiment of the invention providing an impact detonating mechanism for a warhead carrying underwater rocket. A nose 89 of metal is formed or mechanically connected to a casing 91 and forms a forward bulkhead 92 to support an impact detonating fuse means 93. In this instance a simple impact detonator is used which is produced by the Cap-Chur Co. of Atlanta, Ga. Rearward of the detonating means is the warhead 94 which is exploded by the detonating means which is activated upon impact with a target. Rearward of the warhead is a fire wall 96 which is crimped into the casing providing a bulkhead for the rocket propulsion motor similar to that described in FIGURE 4.

FIGURE 7 shows a warhead for use with the rockets of the present invention. Because of the new and novel results effected by these weapons when used as an underwater weapon, these weapons have such penetrating power, as compared with the Weapons of the prior art, that different warhead configurations are considered desirable for use therewith. Generally an underwater spear is constructed for the purpose of penetrating the target and then engaging it to prevent it from being withdrawn. Barbed noses or similar type configurations are used to prevent a fish from shaking the spear out or having it pull free. The weapon of the present invention strikes with such force that it would very possibly pass completely through a fish. Therefore provision is made to insure that the rocket driven spear stays in the fish and delivers all of its energy of impact to the target. This is accomplished by providing a nose 97 with longitudinal striated sections 98 and a hollow point 99. Thus when the nose portion strikes the fish the nose splits and separates into sections along the striation lines and mushrooms. This internally ruptures the fish and creates the larger frontal area to the rocket nose which insures that the rocket does not completely pass through the fish.

In FIGURE 8 a simple arrangement is shown whereby the rockets of the present invention can be combined with presently existing equipment for constructing a simple, inexpensive underwater hand gun. An underwater military demolition lighter fuse 101 model M2 is adapted to a simple firing tube 102 containing a rocket 103 of the present invention. The firing tube is approximately the length of the rocket and has a rearward flange 104 for providing a seat for the fuse pin body and a threaded rear portion to engage the portion of the fuse which is to be used in this embodiment. The rocket is restrained in the launcher by means of the cartridge cap 106 on the rear end of the rocket. A firing pin 107 is held in cocked position, wherein the spring 108 is compressed, by means of a locking pin 109 through the shank of the firing pin. A ring 111 is provided to permit easy removal of the locking pin from the firing pin whereby it is snapped forward into the primer in the cartridge cap on the rocket. This type of weapon arrangement could be used as a one shot device for self defense. In order to use this device as a reloadable reusable mechanism, only slight modifications are necessary as shown in FIGURE 9. The rear end of the fuse body portion could be threaded and a simple handle 112 added thereto whereby the firing pin 113 could be returned to the cocked position. The handle is provided with a longitudinal slot 114- permitting access by the finger of the operator to grip the firing pin and recompress the firing spring. This handle would permit simple operation for firing and recocking the weapon. This type apparatus could be reloaded underwater.

In order to provide a more handy arrangement a simple underwater gun (FIGURE 10) could be constructed. All of the parts of this weapon should be made of a non-corirodible metal, such as nickel or stainless steel, since it is very possible and most likely that this weapon will be used in salt water which is very corrosive to some metals. A barrel 116 is provided which is approximately the length of the rocket spear 117. It is undesirable to make the barrel much longer than the rocket. This prevents the possibility of a hydraulic seal forming in the front end of the launching tube which would detract from the performance of the rocket. The barrel is hinged 118 to permit reloading of the weapon and removal of the expended cap 119. A simple trigger 121 mechanism is provided which actuates a linearly traveling spring loaded firing pin 122. The trigger mechanism can be similar to those found in flare pistols as used by the US. Navy. Practically any single shot, firing pin arrangement can be utilized.

FIGURE 11 depicts an alternate nozzle means for roll stabilization of the rocket. This nozzle is produced by taking a piece of solid rod, having a polygonal cross section, preferably triangular, and twisting it to the desired helical degree. A piece of the twisted rod 123 then inserted and secured into the rocket casing 124 rearwardly of the propellant grain 126 and in spaced relation thereto. This causes a constriction cross section in the exit portion 127 (FIGURE 12) of the casing through which the gases of combustion exhaust. The constricting effect results in providing a nozzle for the rocket. As the gases of combustion egress through this portion of the casing, the helical configuration of the twisted rod causes the gases to flow in such a manner that the linearly momentum thereof is partially converted to include an angular moment which causes the rocket to rotate around the longitudinal The propellant is restrained in the forward end of the combustion chamber by metal tabs 128 from the interior wall of the casing formed by a breaching tool. As with the devices of the previous embodiments, primer cap ignition is also provided which consists of an empty cartridge cap 129 coaxially pressure fitted to the rear end of the casing and including a primer cap 131 which is disposed in a seat at the rear of the cap and provided with a communication port 132 to the interior of the rocket. An igniter fuze 133 extends the length of the perforation and through a hole 134 in the twisted rod. Alternatively, the igniter could be run around the sides of the twisted rod, between the rod and the casing wall, thereby eliminating a hole through the center of the rod. Alternatively, a flash mix material could be disposed on the surfaces of the rod before it is inserted into the casing, which transmits the heat of ignition from the primer cap to the igniter fuze.

FIGURE 12 is an end view taken through plane 1212 of FIGURE 11 showing how the piece of twisted rod is restrained in the casing by means of the flange 136 which is rolled into the rear end of the rocket casing securing the rod therein. A sophisticated version of this embodiment would permit the use of the 4 or 5 or 6 sided rod whereby very small clearances are then provided between the wall of the casing and the rod. In this embodiment, a nozzle would then be formed down the center of the rod with a diverging exit cone or a converging-diverging orifice. This could simply be done by drilling and counterboring. With this arrangement a basic portion of the exhaust gases would be properly constricted for egress through the portion of the rod while only the small portion of the issuing gases would be diverted to escape around the outside of the rod between the casing wall and the rod surfaces. This would permit the basic or the largest portion of the exhaust gases to be used for propelling the rocket and the siphoning off only a smaller percentage of the exhausting gases for providing the angular rotation.

FIGURE 13 is a further alternate nozzle means for providing roll stabilization to the rocket. In this embodiment the skewed vanes 137 are positioned in the rocket nozzle forward of the constricted orifice 138. This is achieved by providing an insert 139 for the rocket casing which has a configuration comparable to a spiral miter gear. The insert tapers to conform to the converging portion of the nozzle cone. The spiral teeth on the insert provide the skewed vanes which divert the gases of combustion exhausting through the nozzle to create the angular moment. The nozzle throat is created by metal forming the nozzle casing over the insert and then metal forming a comparable diverging portion 141 to the casing whereby a converging-diverging nozzle cross section is formed in the rocket casing. Similarly, as with the embodiment of FIGURE 11 a central perforation could be provided in the insert to permit exhaustion of a basic portion of the gases of combustion whereby only a smaller portion is siphoned off to provide the angular turning moment. The skewedness of the vanes can range from one to approximately 35 degrees depending upon the degree of roll stabilization desired and how much of the gases of combustion will be routed through the skewed vanes. Ignition of the propellant grain through this insert can be effected down the center bore by means of an igniter fuze, if one is provided, or by means of an ignitor fuze routed between the vanes or by flash mix inserted on the surface of the insert between the vanes.

All of the above systems have many interchangeable arrangements of nozzles, rocket motors and ignition means, and warheads compatible with each other. The novel solution to the problem of waterproofing the propellant grain and the ignition systems is the use of the cartridge cap as shown in the embodiments of FIG- URES 2, 4, 8, 9,10,11, and 13.

The use of the high powered underwater rockets of the present invention by underwater demolition teams of the Navy has the additional advantage of providing a lethal weapon which can be used for self defense out of the water. The rocket provides such thrusts that the rocket powered projectile will carry for considerable distances in air with excellent accuracy. Thus, the UDT man does not have to carry two types of weapons.

While changes can be made in the details of construction and methods of fabrication of the underwater rockets of the present invention without departing from the spirit and scope of the invention, it is not to be limited except as defined in the following claims.

We claim:

1. An underwater operative miniature ballistic rocket comprising, an elongated cylindrical casing having inner and outer walls and provided with a nose portion at its forward end and a friction-fitted primer filled cartridge head embracing the outer wall adjacent the rearward end thereof, said cylindrical casing further containing an explosive in proximity to said nose portion and a longitudinally extending centrally perforated propellant aligned therewith, a bulkhead interposed between said explosive and the propellant, a valve member between the bulkhead and said propellant and nozzle means positioned within said casing between the propellant and the friction-fitted cartridge head.

2. An underwater operative miniature ballistic rocket as claimed in claim 1, wherein the bulkhead also includes an ignition means, said ignition means including a delay element.

3. An underwater operative miniature ballistic rocket as claimed in claim 1, wherein a booster pellet is positioned within said perforated propellant and in substantial abutting relation with the valve member in said bulkhead.

4. An underwater operative miniature ballistic rocket as claimed in claim 1, wherein a propellant activator is interposed between said perforated propellant and the nozzle means.

5. An underwater operative miniature ballistic rocket as claimed in claim 1, wherein said nozzle means is adapted to impart relative rotation to said rocket upon its becoming disengaged from the friction-fitted cartridge head.

6. An underwater operative miniature ballistic rocket as claimed in claim 1, wherein said nose includes an elongated, slender, forwardly tapered body portion that terminates abruptly into a substantially feathered edge portion defining an annular perforation, said perforation extending longitudinally into said nose to an extent adapted to permit radial outward rupture of the feathered edge portion upon impact with an object.

7. An underwater operative miniature ballistic rocket as claimed in claim 6, wherein the entire perimetrical area of said tapered body portion is provided with striations to facilitate radial rupturing of the nose in proximity to the feathered edge portion.

References Cited UNITED STATES PATENTS 9,047 6/1852 Brand 10248 2,036,292 4/1936 Moore 10292.5 2,356,227 8/ 1944 Diehl 10292.5 2,397,114 3/1946 Anzalone 10249 2,405,415 8/ 1946 Eksergian 10249 2,426,239 8/ 1947 Renner l0238 2,504,648 4/ 1950 Chandler 102-49 2,773,448 12/1956 Iasse 10249 2,789,465 4/ 1957 McDonald.

2,853,946 9/1958 Loedding 10249 2,941,470 6/1960 Iasse 10249 2,972,933 2/1961 Guthrie et al 891.7 3,030,865 4/1962 Ridnour 891.7 3,048,972 8/1962 Barlow 60-356 3,060,854 10/1962 Maretti 11420 X 3,157,026 11/1964 Lambert 60-356 FOREIGN PATENTS 166,015 4/ 1954 Australia. 662,429 12/ 1951 Great Britain.

BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL W. ENGLE, V. R. PENDEGRASS,

Examiners. 

1. AN UNDERWATER OPERATIVE MINIATURE BALLISTIC ROCKET COMPRISING, AN ELONGATED CYLINDRICAL CASING HAVING INNER AND OUTER WALLS AND PROVIDED WITH A NOSE PORTION AT ITS FORWARD END AND A FRICTION-FITTED PRIMER FILLED CARTRIDGE HEAD EMBRACING THE OUTER WALL ADJACENT THE REARWARD END THEREOF, SAID CYLINDRICAL CASING FURTHER CONTAINING AN EXPLOSIVE IN PROXIMITY TO SAID NOSE PORTION AND A LONGITUDINALLY EXTENDING CENTRALLY PERFORATED PROPELLANT ALIGNED THEREWITH, A BULKHEAD INTERPOSED BETWEEN SAID EXPLOSIVE AND THE PROPELLANT, A VALVE MEMBER BETWEEN THE BULKHEAD AND SAID PROPELLANT AND NOZZLE MEANS POSITIONED WITHIN SAID CASING BETWEEN THE PROPELLANT AND THE FRICTION-FITTED CARTRIDGE HEAD. 